Writing instrument holder



FIG. 1 is a front elevation view of the writing instrument holder showing my new design;

FIG. 2 is a rear elevation thereof;

FIG. 3 is a left side, elevation view thereof, the right side being a mirror image of the left side;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a right side, perspective view thereof.

The broken lines showing two writing instruments in FIG. 6 are included for the purpose of showing articles in the environment that form no part of the claimed design. 

The ornamental design for an writing instrument holder, as shown and described. 